Unit for storing a fluid, and method for producing a unit for storing a fluid

ABSTRACT

A unit for storing a fluid includes a body, a piston, and a closure. The body has a through-channel in which the fluid is arranged. The body is impermeable to the fluid and/or constituents thereof and is configured to connect in a fluid-tight manner to a receiving device of a biochemical analysis unit. The through-channel extends from a first end to a second end. The piston is mounted to be axially movable in the through-channel and is configured to provide a fluid-tight seal relative to the body. The piston is impermeable to the fluid and/or constituents thereof and is accessible from the first end. The closure is arranged on the second end and is impermeable to the fluid and constituents thereof. The closure is connected to the body in a fluid-tight manner and is configured to burst when a pressure in the fluid exceeds a bursting pressure.

This application claims priority under 35 U.S.C. §119 to patent application number DE 10 2013 201 297.7, filed on Jan. 18, 2013 in Germany, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure relates to a unit for storing a fluid, to a receiving device for receiving the unit for storing the fluid, to a system for providing the fluid, to a method for producing the unit, and to a method for providing the fluid.

In modem analysis methods, small units are increasingly being used for laboratory analysis, these being configured as a cartridge with components of a disposable laboratory. The reagents needed for an analysis are to be stored in this cartridge. In this context, DE 10 2009 045 685 A1 describes a microfluidic chip with a distensible diaphragm which is distensible into a liquid reservoir, with volume displacement, in order to move a liquid out of the liquid reservoir, through a liquid channel inlet and into a liquid channel of the microfluidic chip.

SUMMARY

Against this background, the present disclosure proposes a unit for storing a fluid, a receiving device for receiving the unit for storing the fluid, a system for providing the fluid, a method for producing the unit, and a method for providing the fluid, according to the description below. Advantageous embodiments are set forth in the description below.

Depending on their nature, plastics may be permeable to some substances while being impermeable to other substances. If different substances are stored in an analysis unit that is made of plastic and has several directly adjoining chambers, it is possible for readily volatile substances to diffuse through the plastic and evaporate, or to contaminate other substances stored in adjoining chambers.

In order to rule out the possibility of contamination by substances diffusing into reagents and auxiliary substances inside an analysis unit of a biochemical analysis method, the reagents and auxiliary substances can be stored in prepared portions in anti-diffusion receptacles, and these receptacles can be opened in an automated manner just shortly before use, and the reagents and auxiliary substances are passed into an analysis area. The reagents and auxiliary substances remain in the analysis area only for the duration of the analysis method. Thereafter, the whole analysis unit can be disposed of. In particular, readily volatile reagents and auxiliary substances can be stored in anti-diffusion receptacles. The anti-diffusion receptacles can be anti-diffusion units with an anti-diffusion closure, which units are opened in response to a switch-over command, such that the reagents and auxiliary substances can flow into the analysis area. The units can be stored inside a receiving device.

A unit is proposed for storing a fluid, in particular a reagent or an auxiliary substance for a biochemical analysis method, wherein the unit has the following features:

a main body with a through-channel, in which the fluid is arranged, wherein the main body is impermeable to the fluid and/or constituents of the fluid and is configured to be connected in a fluid-tight manner to a receiving device of a biochemical analysis unit, wherein the through-channel extends from a first end to a second end;

a piston, which is mounted so as to be axially movable in the through-channel, wherein the piston is configured to provide a fluid-tight seal in relation to the main body, and/or the piston is impermeable to the fluid and constituents of the fluid and is accessible from the first end of the through-channel; and

a closure, which is arranged on the second end of the through-channel, wherein the closure is impermeable to the fluid and/or constituents of the fluid and is connected to the main body in a fluid-tight manner, wherein the closure is configured to burst when a pressure in the fluid is greater than a bursting pressure.

Moreover, a receiving device is proposed for receiving a unit for storing a fluid according to the approach set out here, wherein the receiving device has the following feature:

a receiving opening for receiving the main body, wherein the receiving opening is configured as a through-channel from an outside of the receiving device to an inside of the receiving device, wherein the receiving opening is configured to provide a fluid-tight seal on an outer face of the main body when the main body is arranged in the receiving opening.

Furthermore, a system is proposed for providing a fluid for a biochemical analysis unit, having the following features:

a receiving device according to the approach set out here, wherein the inside is connected fluidically to the analysis unit; and

a unit for storing a fluid according to the approach set out here, wherein the main body is arranged in the receiving opening and the outer face of the main body is sealed off in a fluid-tight manner against the receiving opening, wherein the main body is connected or can be connected non-releasably to the receiving device, and the closure is arranged or can be arranged on the inside.

A method is proposed for producing a unit for providing a fluid, wherein the method has the following steps:

provision of a main body with a through-channel, and of a piston which is mounted so as to be axially movable in the through-channel, wherein the fluid can be arranged in the through-channel, and the main body is impermeable to the fluid and constituents of the fluid and is configured to be connected in a fluid-tight manner to a receiving device of a biochemical analysis unit, wherein the through-channel extends from a first end to a second end, wherein the piston is configured to provide a fluid-tight seal in relation to the main body, and the piston is impermeable to the fluid and/or constituents of the fluid and is accessible from the first end of the through-channel;

filling at least a part of the through-channel with the fluid from the direction of the second end; and

arranging a closure on the second end of the through-channel, wherein the closure is impermeable to the fluid and/or constituents of the fluid and is connected to the main body in a fluid-tight manner, wherein the closure is configured to burst when a pressure in the fluid is greater than a bursting pressure, in order to produce the unit for providing the fluid.

Moreover, a method is proposed for providing a fluid for a biochemical analysis unit, having the following steps:

provision of a system for providing according to the approach set out here; and

moving the piston from the first end into the through-channel until the pressure in the fluid is greater than the bursting pressure, in order to provide the fluid at the second end of the through-channel on the inside.

A main body can be a hollow cylinder, for example. A through-channel can be a bore or generally an opening in the main body. The through-channel can extend rectilinearly, and with substantially a constant cross section, through the main body. The through-channel can have an irregular cross section. Likewise, the main body can have a prismatic shape. In terms of its cross section, the through-channel can be a smaller image of a cross section of the main body. The through-channel can also be shaped independently of the cross section of the main body. For example, the cross section of the main body can correspond externally to a polygon, while the through-channel is cylindrical. In this way, for example, the unit can be identified by the cross section of the main body, thus preventing the main body from being inserted into the wrong receiving device. A piston standardized for use in differently shaped main bodies can be arranged in the inside of the unit, so as to be able to use the same parts in several different units. The piston can have a seal for bearing sealingly on the main body. The piston can be movable along the through-channel. A cross-sectional area of the through-channel can vary from unit to unit, depending on what kind of fluid is arranged in the through-channel. The cross-sectional area may depend on the required amount of the fluid in the biochemical analysis method. The amount of the fluid can also be determined by a stroke length of the piston in the through-channel. A closure can be a lid. The closure can also be a cap or a flap. The main body, the piston and the closure can be made from the same material. The main body, the piston and the closure can also be made from different materials. At the moment of bursting, a connection site between the closure and the main body can break open, for example. Likewise, the closure itself can break open. The pressure can increase when the piston is pressed into the through-channel in the direction of the closure.

A receiving device can be an interface for receiving a unit. The fluid can also be filled into several chambers inside the through-channel. Several different species can then be stored in a single through-channel and can be pressed out together by the piston. The species can be mixed while being pressed out.

The closure can be configured as an anti-diffusion film, which is welded to the main body. Alternatively or in addition, the closure can have a predetermined breaking point. For example, the film can be a laminate of different types of plastics and/or metal film. To close it, at least one layer of the film can be fused to the main body. A predetermined breaking point can be a predetermined area of weakening of the closure which, for example on account of a notch effect, only fails when the pressure is greater than the bursting pressure.

The closure can be configured to close when the pressure in the fluid is lower, by a tolerance pressure, than the bursting pressure. The closure can close again in a fluid-tight manner when the piston remains in one position, for example because only a partial amount of the fluid is needed in the biochemical analysis. For this purpose, for example, the closure can apply restoring forces, which once again close the closure.

A length of the piston can be greater than or equal to a length of the through-channel. Alternatively or in addition, the piston and the through-channel can form a press fit. If the piston is longer than or the same length as the main body, the piston can be pressed along the entire length of the through-channel without aids. A press fit can be an interference fit. If the piston has a slightly larger cross section than the through-channel, the piston can then bear sealingly on the main body, without a further seal being necessary.

The piston can have, on a side facing toward the first end, an actuation surface which is oriented transversely with respect to a direction of movement of the piston. Alternatively or in addition, the piston can have a depth stop, which is configured to limit a depth of penetration of the piston in the through-channel. An actuation surface can be understood, for example, as a seat for a stamp for actuating the piston. Likewise, the area of the actuation surface available for actuating the piston can be greater than the cross-sectional area of the piston. In this way, the piston can be pressed down more easily. For example, the piston can have a thickened part at an end protruding from the main body. A depth stop can be a functional surface on the piston, which functional surface abuts against another functional surface when the piston reaches its maximum planned depth of penetration. The other functional surface can be arranged on the main body. The other functional surface can also be arranged on the receiving device.

The main body can have at least one locking mechanism for connecting the main body non-releasably to the receiving device. Alternatively or in addition, the main body can have at least one stop surface for limiting a depth of insertion of the main body into the receiving device. Alternatively or in addition, the main body can have at least one manipulation surface for manipulation of the unit by a manipulating system. A locking mechanism can be a detent lug, for example. In the latched state, the locking mechanism can no longer be reached manually or by means of an instrument, i.e. it can be concealed, such that the main body can no longer be removed from the receiving device. The main body can also have an engagement surface for a locking mechanism of the receiving device. Receiving device and main body can engage one inside the other. A stop surface can bear on another stop surface of the receiving device when the main body is arranged at an intended position. A manipulation surface can be configured, for example, as a mating piece for a gripper. The unit can be held at the manipulation surface in an automated manner, for example in order to be transported for filling or to be inserted into the receiving device.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is explained in more detail below on the basis of examples and with reference to the attached drawings, in which:

FIG. 1 shows a block diagram of a system for providing a fluid for a biochemical analysis unit according to an illustrative embodiment of the present disclosure;

FIG. 2 shows a flow diagram of a method for producing a unit for providing a fluid according to an illustrative embodiment of the present disclosure;

FIG. 3 shows a flow diagram of a method for providing a fluid for a biochemical analysis unit according to an illustrative embodiment of the present disclosure;

FIG. 4 shows a sectional view of a detail from a system for providing a fluid for a biochemical analysis unit according to an illustrative embodiment of the present disclosure; and

FIG. 5 shows a view of a system for providing a fluid, with two units according to an illustrative embodiment of the present disclosure.

In the following description of preferred illustrative embodiments of the present disclosure, identical or similar reference signs are used for the elements that are shown in the various figures and that have a similar effect, the aim being to avoid repeated description of these elements.

DETAILED DESCRIPTION

FIG. 1 shows a block diagram of a system 100 for providing a fluid 102 for a biochemical analysis unit according to an illustrative embodiment of the present disclosure. The fluid 102 can be used in particular as a reagent or an auxiliary substance for a biochemical analysis method. For example, the fluid 102 can be alcohol or an alcohol mixture containing at least 75% alcohol. The system 100 consists of a unit 104, for storing the fluid 102, and of a receiving device 106. The unit has a main body 108, a piston 110 and a closure 112. The receiving device 106 has a receiving opening 114, a supply chamber 116, and a channel 118 leading to a biochemical analysis unit (not shown) for carrying out a biochemical analysis method.

The unit 104 for storing the fluid 102 has been inserted non-releasably into the receiving device 106 after the unit 104 has been produced. The unit 104 and the receiving device 106 are connected to each other in a fluid-tight manner. The main body 108 of the unit has a central through-channel 120, in which the fluid 102 is arranged. The main body 108 is made from a material that is impermeable to the fluid 102 and constituents of the fluid 102. The through-channel 120 extends from a first end to a second end of the main body 108. The piston 110 is mounted so as to be axially movable in the through-channel. The piston 110 is sealed off in a fluid-tight manner in relation to the main body 108. The piston 110 is made from a material that is impermeable to the fluid and constituents of the fluid. The piston 110 is accessible from the first end of the through-channel. The closure 112 is arranged on the second end of the through-channel 120. The closure 112 is made from a material that is impermeable to the fluid and/or constituents of the fluid. The closure 120 is connected to the main body 108 in a fluid-tight manner. The closure 112 is configured to burst when a pressure in the fluid 102 is greater than a bursting pressure.

The receiving opening 114 is configured to receive the main body 108. The receiving opening 114 is configured as a through-channel from an outside of the receiving device 106 to an inside of the receiving device 106. The receiving opening 114 is configured to provide a fluid-tight seal on an outer face of the main body 108 when the main body 108 is arranged in the receiving opening 108.

The unit 104 can be made from a material that prevents diffusion of solvents, in particular alcohol. The material can be a polymer in particular. In this way, solvent-containing, in particular alcohol-containing, fluids or liquids and/or pastes can be stored in the unit 104 permanently and without loss, until they are needed. Moreover, fluids that tend to denature can be protected in the unit against solvent vapors, in particular alcohol vapors. The receiving device 106 can in turn be produced from an inexpensive and easily formable material, since the fluid and other fluids remain in the receiving device only for the duration of the biochemical analysis method, and there is not enough time for diffusion processes.

By using a syringe container 104, an advantageous plastic (COC, PP, PE) or steel can be used for the storage of alcohol as fluid. The plastic of the syringe container 104 can be chosen independently of the plastic of the cartridge 106. Thus, the cartridge 106 can be configured using an inexpensive plastic with high alcohol permeation rates (e.g. PC).

By the actuation of the syringe 104, the liquid 102 is always forced out by 100%, and there is no loss of expensive reagents in the LOC fluid network 116, which leads to cost optimization of expensive PCR primers. In addition, the liquid 102 can be provided in metered amounts, which leads to an improved process. Small amounts (a few μl) of liquids 102 can be stored in a stable state over a long period of time and can be provided 100% for the assay. This leads to a quality improvement in the course of the assay.

By the movement of the piston 110, low-viscosity liquids 102 can be stored and safely forced out. Forcing them out by a volume displacement constitutes a flexible and robust system. The syringes 104 can be used as additional reservoirs on the cartridge 100 during the process, as a result of which a reduction in the overall size is permitted. By means of a two-chamber system inside the syringe 104, liquids 102 can be mixed inside the syringe 104, thereby permitting a further reduction in the overall size of the cartridge 100.

FIG. 2 shows a flow diagram of a method 200 for producing a unit for providing a fluid according to an illustrative embodiment of the present disclosure. The method 200 has a step 202 of providing, a step 204 of filling, and a step 206 of arranging. In the step 202 of providing, a main body with a through-channel, and a piston which is mounted so as to be axially movable in the through-channel, are provided. The fluid can be arranged in the through-channel. The main body is impermeable to the fluid and/or constituents of the fluid. The main body is configured to be connected in a fluid-tight manner to a receiving device of a biochemical analysis unit. The through-channel extends from a first end to a second end. The piston is configured to provide a fluid-tight seal in relation to the main body and is impermeable to the fluid and constituents of the fluid. The piston is accessible from the first end of the through-channel. In the step 204 of filling, the through-channel is filled with the fluid from the second end. In the step 206 of arranging, a closure is arranged on the second end of the through-channel. The closure is impermeable to the fluid and constituents of the fluid and is connected to the main body in a fluid-tight manner, in order to produce the unit for providing the fluid. The closure is configured to burst when a pressure in the fluid is greater than a bursting pressure.

FIG. 3 shows a flow diagram of a method 300 for providing a fluid for a biochemical analysis unit according to an illustrative embodiment of the present disclosure. The method 300 has a step 302 of providing, and a step 304 of moving. In the step 302 of providing, a system for providing according to the approach set out here is provided. In the step 304 of moving, the piston is moved from the first end into the through-channel until the pressure in the fluid is greater than the bursting pressure, in order to provide the fluid at the second end of the through-channel on the inside.

FIG. 4 shows a sectional view of a detail of a system 100 for providing a fluid for a biochemical analysis unit according to an illustrative embodiment of the present disclosure. FIG. 4 thus shows a cross section of a clipped-in syringe 104 in the cartridge 106. The system 100 corresponds to the system in FIG. 1. In addition, the piston 110 has a length that is greater than a length of the main body 108. Therefore, in the filled state of the unit 104 as shown, the piston 110 protrudes with a free end above the main body 108. The piston 110 has an actuation surface 400 at the free end. The actuation surface 400 is oriented transversely with respect to a direction of movement of the piston 110. The actuation surface 400 is many times greater than a cross-sectional surface of the piston 110. A movement of the piston 110 is made easier by the size of the actuation surface 400. A collar 402 is arranged on an edge of the actuation surface 400. The collar 402 is oriented transversely with respect to the actuation surface 400 and points in the direction of the receiving device 106. The collar 402 is configured extending peripherally about the actuation surface 400. A sectional plane of the piston 110, of the actuation surface 400 and of the collar 402 has the shape of an upper-case letter T with serifs on the horizontal stroke. The piston 110 represents the stem of the letter, the actuation surface 400 represents the horizontal stroke, and the collar 402 represents the serifs. The collar 402 is configured to act as a depth stop for the piston 110. During the actuation of the piston 110, the piston 110 can be pressed into the main body 108 until a stop surface 404 of the collar 402 bears on an outside of the receiving device 106.

The main body 108 is configured as a hollow cylinder in this illustrative embodiment. The main body has a locking mechanism 406 for connecting the main body 108 non-releasably to the receiving device 106. In this illustrative embodiment, the locking mechanism 406 is configured as a plurality of springs 406 protruding from the main body 108. Upon insertion of the unit 104 into the receiving device 106, the springs 406 are each configured to be bent and to latch onto a projection 408 of the receiving device 106. For this purpose, the receiving device 106 has, in the area of the through-channel 114, pockets 410, which form the projections 408. Between the pockets 410 and the inside, a sealing face 412 is arranged, at which the unit 104 seals off the through-channel 114 in a fluid-tight manner when the unit 104 is connected to the receiving device 106. In the inserted state, the springs 406 bear on that face of the pockets 410 directed toward the inside and thus represent the stop surface for limiting the depth of insertion of the main body 108. Between the outside and the pockets 410, the through-channel 114 has widenings in order to make space available for the insertion of the springs 406. When the springs 406 are arranged in the pockets 410, they extend diagonally through the pockets 410 and prevent removal of the unit 104 from the receiving device 106. As in FIG. 1, the through-channel in the main body 108 is covered by a film acting as a closure 112. The film is integrally bonded to the main body 108. In order to obtain a controlled bursting of the closure 112, the film can have a predetermined breaking point. Similarly, for example, a partial area of a connection site between the closure 112 and the main body 108 can be configured to be weaker than the rest of the connection site, such that the closure fails in a controlled manner in the partial area.

In contrast to FIG. 1, the receiving device 106 does not have a supply chamber here. The closure 112 is arranged directly in the channel 118, while the main body 104 protrudes into the channel 118.

In other words, the reagents are filled into so-called syringes 104. FIG. 4 shows a cross-section of a clipped-in syringe 104 in the cartridge 106. These syringes 104 can be filled outside the cartridge 106 and are then sealed by an adhesive film 112. All of the syringes 104 are clipped into the cartridge 106 during the production process, with alternative securing options also being possible, for example screwing or clamping. The syringes 104 can be protected by a lid, as in FIG. 5, against accidental actuation during transport. During the provision of the fluid, the DxU (DxU=Diagnostic Unit) presses on the piston 110 with a force F and thus actuates the syringe 104. A DxU can be understood as an evaluation device into which the cartridge is fitted and by which the cartridge is operated. The evaluation unit also represents the interface to the user for displaying the results. The amount of the reagent that is provided can be determined by the distance traveled and by a defined stop 404 in the cartridge 106. In addition, the volume of the syringe 104 can be varied by the diameter of the piston 110. For actuating the piston 110, no sealing elements are needed between DxU and cartridge 100. The sealing elements are already integrated in the cartridge 106 and syringe 104.

FIG. 5 shows a view of a system 100 for providing a fluid, with two units 104 according to an illustrative embodiment of the present disclosure. The units 104 correspond to the unit in FIG. 4. Both units 104 are arranged alongside each other. The units 104 are inserted into a common receiving device 106 and latched non-releasably. The receiving device 106 has two through-holes arranged alongside each other. The through-holes can open into a common mixing chamber in order to mix the fluids of both units 104. Likewise, the through-holes can also each open into a respective supply chamber, so as to be able to be used separately for the biochemical analysis method. In order to protect the units 104 against accidental actuation, the actuation surfaces 400 are covered by a protective cap 500. The protective cap 500 is secured on the receiving device 106 and is intended to be removed before the system 100 is used, such that the actuation surfaces are exposed. The protective cap 500 also protects the units 104 from environmental effects, in particular contamination. In this way, an analysis appliance can be kept clean when the analysis unit, with the providing system 100 secured thereon, is inserted.

In other words, FIG. 5 shows a lab-on-a-chip (LOC) cartridge 100 with integrated syringes 104 for storing reagents. In lab-on-a-chip (LOC) products or so-called microfluidic platforms (μTAS), medical and biological liquids are processed on a substrate and, in this way, samples from patients are analyzed for the presence of pathogens and bacteria. The lab-on-a-chip platforms can be constructed as so-called cartridges which, as disposable articles, receive and process the patient sample. Liquids are needed for the process carried out on the cartridge, which liquids can either be stored on the cartridge or can subsequently be added for the process by a user. The subsequent introduction of the reagents, even of alcohol-containing substances, can be avoided by the approach set out here, since this is provided just shortly before the assay is performed. Thus, the high permeation rates of the alcohol in favorable plastics is unimportant.

The approach set out here allows all the reagents of a lab-on-a-chip assay to be stored in a stable state over a long period of time on the cartridge 100. In particular, with the storage units 104 set out here, reagents containing alcohol or reagents in small amounts can be safely stored inside the LOC cartridge 100. The illustrated system 100 makes storage safe during transport, and it permits simple opening and provision of the reagents in the case of use. All the pistons of the syringes 104 of a cartridge 106 can be connected by a beam, which is pressed down by the DxU and thus empties the syringes 104 simultaneously.

The illustrative embodiments that have been described and that are shown in the figures are chosen only as examples. Different illustrative embodiments can be combined with one another as a whole or in terms of individual features. An illustrative embodiment can also be supplemented by features of another illustrative embodiment.

Moreover, method steps according to the disclosure can be repeated and can also be carried out in a different sequence than that described.

Where an illustrative embodiment comprises an “and/or” link between a first feature and a second feature, this is to be understood as meaning that the illustrative embodiment, in one form, has both the first feature and also the second feature and, in another form, has either only the first feature or only the second feature. 

What is claimed is:
 1. A unit for storing a fluid, the unit comprising: a main body with a through-channel in which the fluid is arranged, the main body impermeable to the fluid and/or constituents of the fluid, the main body configured to be connected in a fluid-tight manner to a receiving device of a biochemical analysis unit, the through-channel configured to extend from a first end to a second end; a piston mounted so as to be axially movable in the through-channel, the piston configured to provide a fluid-tight seal in relation to the main body, the piston impermeable to the fluid and/or constituents of the fluid, the piston accessible from the first end of the through-channel; and a closure arranged on the second end of the through-channel, the closure impermeable to the fluid and/or constituents of the fluid and connected to the main body in a fluid-tight manner, the closure configured to burst when a pressure in the fluid is greater than a bursting pressure.
 2. The unit according to claim 1, wherein the closure is configured as an anti-diffusion film welded to the main body.
 3. The unit according to claim 1, wherein the closure is configured to close when the pressure in the fluid is lower than the bursting pressure by a tolerance pressure.
 4. The unit according to claim 1, wherein a length of the piston is greater than or equal to a length of the through-channel.
 5. The unit according to claim 1, wherein the piston has, on a side facing toward the first end, an actuation surface oriented transversely with respect to a direction of movement of the piston.
 6. The unit according to claim 1, wherein the main body has at least one locking mechanism configured to connect the main body non-releasably to the receiving device.
 7. The unit according to claim 1, wherein the receiving device of the biochemical analysis unit includes a receiving opening configured to receive the main body, the receiving opening configured as a through-channel from an outside of the receiving device to an inside of the receiving device, the receiving opening configured to provide a fluid-tight seal on an outer face of the main body when the main body is arranged in the receiving opening.
 8. A system for providing a fluid for a biochemical analysis unit, the system comprising: a unit for storing a fluid, the unit including: a main body with a through-channel in which the fluid is arranged, the main body impermeable to the fluid and/or constituents of the fluid, the through-channel configured to extend from a first end to a second end; a piston mounted so as to be axially movable in the through-channel, the piston configured to provide a fluid-tight seal in relation to the main body, the piston impermeable to the fluid and/or constituents of the fluid, the piston accessible from the first end of the through-channel; and a closure arranged on the second end of the through-channel, the closure impermeable to the fluid and/or constituents of the fluid and connected to the main body in a fluid-tight manner, the closure configured to burst when a pressure in the fluid is greater than a bursting pressure; and a receiving device configured to receive the unit such that the main body is connected in a fluid-tight manner to the receiving device, the receiving device including a receiving opening configured to receive the main body, the receiving opening configured as a through-channel from an outside of the receiving device to an inside of the receiving device, wherein the inside is connected fluidically to the analysis unit, wherein the main body is arranged in the receiving opening and the outer face of the main body is sealed off in a fluid-tight manner against the receiving opening, and wherein the main body is configured to be connected non-releasably to the receiving device and the closure is configured to be arranged on the inside.
 9. A method for producing a unit for providing a fluid, the method comprising: mounting a piston so as to be axially movable in a through-channel of a main body, the through-channel configured to receive the fluid, the main body impermeable to the fluid and constituents of the fluid, the main body configured to be connected in a fluid-tight manner to a receiving device of a biochemical analysis unit, the through-channel configured to extend from a first end to a second end, the piston configured to provide a fluid-tight seal in relation to the main body, and the piston impermeable to the fluid and/or constituents of the fluid and accessible from the first end of the through-channel; filling at least a part of the through-channel with the fluid from a direction of the second end; and arranging a closure on the second end of the through-channel, the closure impermeable to the fluid and/or constituents of the fluid and connected to the main body in a fluid-tight manner, the closure configured to burst when a pressure in the fluid is greater than a bursting pressure.
 10. The system according to claim 8, wherein the piston is configured to move from the first end into the through-channel until the pressure in the fluid is greater than the bursting pressure to provide the fluid at the second end of the through-channel on the inside.
 11. The unit according to claim 1, wherein the closure has a predetermined breaking point.
 12. The unit according to claim 1, wherein the piston and the through-channel form a press fit.
 13. The unit according to claim 1, wherein the piston has a depth stop configured to limit a depth of penetration of the piston in the through-channel.
 14. The unit according to claim 1, wherein the main body has at least one stop surface configured to limit a depth of insertion of the main body into the receiving device.
 15. The unit according to claim 1, wherein the main body has at least one manipulation surface configured to enable manipulation of the unit by a manipulating system. 